The most common container used in todays society for keeping food, beverages, fish or fowl from spoiling while outdoors is a rigid insulated cooler. Sportsmen and picknickers generally use ice in block or crushed form to keep the contents cold, for this is its basic purpose.
Several problems are generally encountered when using this method. First, if the rigid cooler is not clean prior to placement of contents, an undesirable atmosphere is used for storage. Second, it needs to be kept clean while in use. Third, upon placement of ice in the cooler, the ice begins to melt into a liquid. This liquid is then free to move about the cooler around the contents allowing the water to come in contact with them. Fourth, if one is using the cooler for fishing or hunting, any meat stored in the cooler is able to intermingle with the food and/or beverages. This can lead to unpleasant conditions both through asthetics and taste. Fifth, after the cooler and contents are brought back for further use or disposal, a dirty cooler is left behind, requiring cleaning before storage or the next use.